Examples of electronic apparatuses incorporating a touch panel are described in Patent Documents 1 and 2. The electronic apparatus described in Patent Document 1 is characterized in that a module having a display member and a circuit board and a touch panel placed on the module are accommodated in a case with a display window and that the apparatus has a shield body equipped with a frame-shaped portion with a display opening and connection pieces for electrically connecting the case and the module, wherein the shield body is provided with positioning units for positioning the shield body and the module and pressing pieces for biasing the touch panel to position the module and the touch panel, the relative positions of the shield body, the module and the touch panel are determined via the shield body, and the shield body encloses the edge portions of the module and the touch panel to effectively block static electricity and noise.
The electronic apparatus described in Patent Document 2 has a main body case having a display opening, a display panel disposed so as to correspond to the opening inside the main body case, a conductive shield member covering the display panel except the display area corresponding to the opening of the display panel and connected to a reference potential, and waterproof cushion members disposed between the outer peripheral portion of the surface of the display panel and the shield member and between the shield member and the main body case so that impacts from the outside can be absorbed and waterproofness can be ensured using the cushion members.
A resistive film type, an electromagnetic induction type, an electrostatic capacitance type, etc. are available as touch panel types; the resistive film type is used in the electronic apparatus described in the above-mentioned Patent Document 1, and the type used in the electronic apparatus described in the above-mentioned Patent Document 2 is not specified. Since the electrostatic capacitance type is used in the present invention, the basics of this type will be described. FIG. 25 is a view showing the basic configuration of an electrostatic capacitance type touch panel. In the figure, an electrostatic capacitance type touch panel 90 has a dielectric 100, a transmission electrode 101, a reception electrode 102 and a driving butter 103, and the transmission electrode 101 and the reception electrode 102 are disposed so as to be separated from each other on the lower face of the plat-shaped dielectric 100. Drive pulses are applied from the driving butter 103 to the transmission electrode 101. When the drive pulses are applied, an electric field is generated from the transmission electrode 101; when a hand 104 enters this electric field, the number of the electric lines of force between the transmission electrode 101 and the reception electrode 102 decreases, and this change in the number of the electric lines of force is expressed as the change in charge in the reception electrode 102. Hence, the proximity of the hand 104 to the touch panel 90 can be detected. In addition, not only the proximity of the hand 104 to the touch panel 90 but also the position (coordinates) of the hand 104 can be detected by providing a plurality of transmission electrodes 101 and a plurality of reception electrodes 102. In other words, the coordinates of a fingertip hovering above the touch panel 90 can be detected.
FIGS. 26(a) to 26(c) are views showing finger detection states at the time when a fingertip 104a is gradually brought close to the touch panel 90. In the figures, FIG. 26(a) shows a state in which the fingertip 104a is away from the electric field. FIG. 26(b) shows a finger hovering detection state in which the fingertip 104a has entered the electric field. FIG. 26(c) shows a finger touch detection state in which the fingertip 104a has entirely entered the electric field and touches the touch panel 90. In the case that the fingertip 104a touches the touch panel 90 to operate it, the apparatus does not malfunction; however, in the case that the hand 104 touches the touch panel 90 at the time when the hand 104 simply holds the main body of the apparatus, the apparatus becomes in a malfunctioning state.